Process for producing tobacco foils

ABSTRACT

Tobacco foils are produced by dusting tobacco particles with a cellulose derivative; moistening the dusted particles with an organic solvent and pressing the moistened particles into tobacco foil. This processing sequence eliminates the need for forming tobacco-cellulosesolvent pulps as previously practiced by the art. Apparatus for performing this process is also described.

o 1 I 11 1 mm 19 [11] 3,865,120

Detert et a1. 1 1 Feb. 111, 1975 [54] PROCESS FOR PRODUCING TOBACCO 3.012.562 12/1961 Merritt 131/17 AC FUELS 3.053.259 9/1962 Parmele et 111.. 131/140 c 3.062.688 11/1962 Detert et 131/17 AC Inventors: Ernst-K911991911, Lubbecke, 3.125.098 3/1964 Osborne 131/17 AC Westphaiia; WilliBuchholz, 3.322.130 5/1967 Panzer et a1 131/17 Lubbecke, of Germany FORElGN PATENTS OR APPLlCATlONS 1 Assigneel Edward Garlach 21,087 4/1961 Germany 131/17 AC Westphalia, Germany 1,215,567 4/1966 Germany 131/17 A Filed. Nov 4 1971 1,137,988 10/1962 Germany 131/17 AC [21] App]. No.: 195,585 Primary ExaminerMe1vin D. Rein Attorney, Agent, or Firm-Molinare, Allegretti, Newitt [30] Foreign Application Priority Data & Wltcoff Nov. 12, 1970 Germany 2055672 [57] ABSTRACT 52 us. ca 131/140 (3, 131/17 AC Tobacco foils are Produced by dusting tobacco p 511 1111. C1 A24b 03/14 C165 with a Cellulose derivative; moistening the dusted 5s Fieid of Search 131/140 c, 136. 17, 15, Particles with an Organic Solvent and Pressing the 131/140444 moistened particles into tobacco foil. This processing sequence eliminates the need for forming tobacco- [56] References Cited ce11u1oses01vent pulps as previously practiced by the UNITED STATES PATENTS art. Apparatus for performing this process is also desc ibed. 2,769,734 11/1956 Bande] 131/15 r 3,009,836 11/1961 Samfield et a1. 131/17 AC 7 Claims, 3 Drawing Figures 'PATENTEDFEBWQYS $865,120

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FIGQZ T IN VEN TORS EMEFR /F 0525M AM 60% 1 PROCESS FOR PRODUCING TOBACCO FOILS BACKGROUND OF THE INVENTION The invention relates to a process for producing tobacco foils using tobacco, binders in the form of cellulose derivatives and solvents. The invention also relates to an apparatus for performing the process.

It is known to produce tobacco foils by processing a very finely ground tobacco dust with a solution ofa cellulose derivative to form a pulp which is shaped into a strip with machines, whereby the binder is a mixture of acetyl cellulose or ethyl cellulose and highly methylated but still water-soluble methyl cellulose. Methylene chloride and methanol are used as solvents.

It is also known to produce tobacco foils which are to be used as a covering or wrapping foil in place of a natural tobacco leaf by processing to a pulp, tobacco dust with cellulose derivatives e.g. acetyl cellulose soluble in organic solvents in the presence of a solvent such as acetone, ether and alcohol which is brought to the desired foil form. The use of water-soluble cellulose derivatives, including methyl cellulose is also known.

These two known processes have a have a large number of disadvantages, particularly the high solvent content which represents a multiple of the solid content. The solvent, which can be water or an organic solvent, after producing the tobacco foil must be expelled again using a large amount of energy in the form of heat so that the tobacco foil dries.

When using a readily volatile organic solvent, high costs also result from the desirable and necessary recovery of the solvent.

Another disadvantage of the tobacco foils produced from a viscous suspension is that the starting material used is tobacco dust requiring a long grinding process requiring a high energy consumption and complicated machinery.

In addition, disadvantages are inherent in the known finished products e.g., when using water as the solvent for the cellulose derivative, the limited saliva resistance of the tobacco foil and the impairing of color and flavor occur, e.g., due to the high cellulose content.

It is also known to produce a strip-like tobacco product by pasting a very fine carrier fabric of cellulose material with finely ground tobacco.

SUMMARY OF THE INVENTION According to the invention, a process for producing tobacco foils is now produced which substantially or completely eliminates the disadvantages of the known tobacco foil production processes leading to products which are very similar to the natural tobacco leaf, contain only a very small amount of binder and require only a small amount of solvent in their production.

This is achieved in that tobacco particles in the size range to mm are dusted with a solvent-soluble, finely ground cellulose derivative and then moistened with an organic solvent, whereafter the tobacco particles obtained are converted into a granulate which is pressed mechanically into a foil. The tobacco particles processed can be the natural tobacco debris of the tobacco industry which can comprise tobacco leaf and vein particles.

The organic anhydrous solvents are e.g., readily volatile alcohols, chlorinated hydrocarbons, ketones, ethers, esters and mixtures thereof. The preferred readily volatile alcohols are methanol, ethanol or isopropanol; the preferred chlorinated hydrocarbons are methylene chloride and chloroform; the preferred ketones are acetone and methylethyl ketone; the preferred esters are acetic ester, methyl and ethyl acetate; and, the preferred ethers are diethyl ether and dimethyl ether.

As a function of the type of foil to be produced i.e. whether it is to be used as a covering or wrapping foil or as a filler, the tobacco starting material can be preclassified. For a covering foil, a tobacco and vein starting material is preferably used with. a particle size of 50 to mu; for a. wrapping foil, a material with a parti cle size of 0.1 to 1 mm; but for a filler foil, a starting material with a particle size of about 1 to 10 mm diameter.

According to the process of the invention, even after processing to a foil, the tobacco substantially retains its own color and structure. By selection of the starting tobacco a covering or wrapping foil can be produced having the desired appearance of the covering or wrapper for the finished article for smoking. 7

The solvent-soluble cellulose derivative e.g. methyl cellulose, methylpropyl cellulose, acetyl cellulose or ethyl cellulose used as the binder is, according to the invention, very finely ground (particle size 0-0.2mm) and powdered onto the tobacco particles serving as the starting material and, namely, in the dry state. The powdering of the tobacco particles gives the otherwise brown tobacco particles a grey-brown appearance which means that the cellulose derivative particles are distributed more loosely on the tobacco particles and do not completely cover the surface of the foil of tobacco particles. This cellulose derivative is powdered onto the tobacco particles in a mixer wherein, together with the mixing action, a kneading effect is achieved and onto which are introduced the tobacco particles and the necessary amount of ground cellulose derivative. Following this mechanically performed powdering process, the solvent is added to the mixer. It is also, however, possible to transfer the powdered tobacco particles to another mixer to which is added the sol vent.

According to the invention only such a quantity of solvent, is added as to moisten the tobacco particles and ensure the superficial swelling of the cellulose derivative particles located on the tobacco particles.

The tobacco material treated in the mixer forms, after adding the solvent, a granulate which is subsequently supplied to an apparatus which presses the granules into a foiHike form. It has been found that this mechanical pressing process is advantageously performed with a roller mill with two contra-rotating rollers with polished surfaces or hardened steel.

The granules of solvent-moistened tobacco particles powdered with cellulose derivative are supplied to the roller inlet, whereby advantageously a uniform distribution of the granules is brought about which are pressed into a foil by means of counter-rotating rollers.

It has been surprisingly found that the tobacco particles when moistened with solvent become brittle making the pressing process particularly advantageous be cause the tobacco granules consequently, shatter instead of smearing.

If the tobacco starting material is e.g., a relatively coarse starting material with a high vein content and a particle size of 1 to 10 mm, after the first pressing in the two-roller mill a foil is also produced which does not have a completely closed structure but, instead, is porous or it may even be in the form of a structure comprising individual tobacco foil sheets interconnected via individual strands. Naturally, this material can not be used as a foil but it can be employed as an enclosure for a product for smoking. If, however. a closed product is required from such a material, then the product obtained after the first pressing on two-roller mill can be supplied to a further roller mill with three rollers and subjected to a further pressing. The thrid roller serves to remove the closed foil formed and convey the foil to an apparatus for removing the solvent.

If the production of a covering foil is based on a tobacco and vein dust of particle size 50 to 100 m, i.e. a relatively fine-particle starting material, then the tobacco particle granulate dusted with cellulose derivative and moistened witha solvent can be supplied directly to the three-roller mill which then transfers it to the foil drying apparatus because after only a single passage through a roller mill a good foil is obtained. The same obviously applies for coarser tobacco starting material if the desired use of such a material permits. ln producing a wrapping foil for which tobacco particles of diameter 0.1 to 1mm are used, then the threeroller mill can be directly used, whereafter the finished foil is supplied to the further processing apparatus.

According to the invention, it is also possible either by selecting the tobacco particles or by the mechanical processing process to obtain a particular product suitable fora particular purpose.

EXAMPLES Thus, to produce a covering foil e.g. the following ingredients would be used:

132.0 kg. of tobacco and vein dust with a particle size of to m hol, together with the glycols acting as softeners are introduced into the mixer where the dusting was performed or into another mixer into which the powdered tobacco dust has been placed and mixed until a maximum uniform saturation of the tobacco material with the solvents and softeners has taken place.

Similarly, for producing a wrapping or a wrapping foil, the following would be used:

132.0 kg. of tobacco and vein debris with a particle size of 0.1 to 1 mm. 22.0 kg. of methyl cellulose 11.0 kg. of diethylene glycol 160.0 kg. of methylene glycol 40.0 kg. of methyl alcohol For a filler foil, the following ingredients are suitable: 132.0 kg. of tobacco and vein debris with a particle size of diameter 1 to 10 mm 16.0 kg. of methyl cellulose 8.0 kg. of 1,3-butylene glycol 125.0 kg. of methylene chloride 31.0 kg. of methyl alcohol The example of the production of an insert foil, clearly shows that the tobacco and vein debris obtained in the tobacco-processing industry can be processed into a usable tobacco material and, unlike in the known tobacco foil production process, this material does not have to pulverised in a further time-consuming and costly grinding process. As these tobacco particles can be directly processed according to the inventive process in the natural size obtained then the resulting foil has a tobacco leaf-like structure. The glycol, namely, diethylene glycol and 1,3-butylene glycol indicated in the composition examples serves as a softener as a result of which the foil becomes flexible and, due to water or moisture absorption, remains flexible.

The following table gives further compositions for 15.0 kg. of methyl cellulose 40 pr ducing tobacco products.

TABLE Material 1 2 3 4 5 6 7 8 Wrapping Light Dark Single- Brown Light Cigar Cigarette covering covering sheet cigarette cigarette filler filler foil tube tube Brazilian tobacco 100 4O Sumatra tobacco 132 132 32 132 132 Virginia tobacco 60 70 132 Methyl cellulose 22 15 15 23 25 25 18 18 Acetyl cellulose 7 7 7 12 12 1,3-butylene glycol 5 5 5 15 15 10 Diethylene glycol 1 1 6 6 l0 l0 Methylene glycol 160 I60 160 160 160 160 I6 Methanol 4O 4O 40 4O 40 40 4O 40 Titanium dioxide 2 25 Calcium carbonate 2 5 Magnesium oxide 3 3 5 5 The tobacco used can consist of blends from various Sources.

7.0 kg. 6.0 kg. 5.0 kg.

DESCRlPTlON OF THE DRAWINGS The further processing of the foils produced according to the process takes place in known manner. An example of an apparatus for performing the process for producing the above-described tobacco foils is shown in the attached drawing wherein: 7

FIG. 1 is an apparatus for performing the process.

FIG. 2 is a tobacco particle after dusting with ground dry cellulose derivative.

FIG. 3 is a schematic representation of a powdered tobacco particle after producing the granulate with the added solvent.

In FIG. 1, I is a mixer wherein the tobacco particles are mixed with the finely ground cellulose derivative. The finely ground cellulose derivative is preferably a fraction having particles in the range to 0.2mm and whereof, preferably at least 50% are below 0.1 mm. The particle size of the cellulose derivative is also de termined by the tobacco particle size.

When the mixing process has progressed until maximum homogeneity has been achieved and the tobacco particles have been dusted with the finely ground cellulose derivative, the solvent is added, followed by a further mixing process. The solvent addition can take place in the same mixer as that in which the tobacco particles have been mixed with the cellulose derivative. It is also, however, possible to place the product of the mixture, tobacco particles and cellulose derivative in a second mixture and only then add the solvent. The subsequent mixing process is continued until a maximum uniform saturation of the powdered tobacco particles takes place. The tobacco particles can be mixed with the finely ground cellulose derivative and solvent in any suitable mixer e.g. in an Eirich mixer wherein counterflow movement takes place between a mixing trough and mixing blades or in a suitable drum mixer which, in addition to mixing simultaneously exerts a kneading action.

FIG. 2 shows schematically a tobacco particle T whereon the dusting operation is demonstrated. It can be seen how the cellulose derivative particles, represented as specks, are only loosely deposited on the tobacco particles T.

FIG. 3 shows the action of moistening the dusted tobacco particles with the solvent. The solvent must not make the tobacco particle mass wet and convert it into a pulp, as in the conventional processes, but instead, the cellulose derivative particles located on the tobacco particles are only made to swell. The solvent is, indeed, absorbed by the tobacco particles, however, at the contact point between the cellulose derivative particle Z and the tobacco particle. The solvent passes over into the former and converts the latter into ajellylike state.

The cellulose derivative e.g. together with the tobacco particles can be placed in the mixer at 2 in the measured and necessary quantities, whereafter following the requisite mixing time of about minutes, solvents and softeners are intorduced into the mixer via pipe 3. The end product of this two-stage mixing process is then, depending on which tobacco particle starting material is used and/or on which end product is to be produced, supplied to a roller mill 4 with two rollers, or to a roller mill 5 with three rollers, or to roller mill 4 followed by roller mill 5. In the production of filler foils (sheets) to which end coarse tobacco, so-called tobacco debris, is used, the mixing product is first supplied to roller mill 4 and then to roller mill 5. In the procan be recovered to be reused for producing tobacco foils. As the solvent portion in the process, according to the invention, represents only one-eighth to onetenth, compared with the known processes, based on tobacco dust and a paste i.e. a viscous pulp, for producing a foil the suction installation 8 and recovery apparatus can be considerably simplified and only a limited vacuum is required in the suction installation. without additional heat, to remove the solvent from the tobacco foil. To the suction installation 8 at the end of conveyor belt 7 is connected a longitudinal and transverse cutting device 9 for producing sheets or foil conveying and cutting device 10 for producing :reels. To the suction installation 8 are also connected roller mills 4 and 5 to which end the roller mills are placed in housings ll.

The-process of the invention not only provides an improved product more closely resembling the natural tobacco leaf but also has numerous other advantages. Firstly, it is no longer necessary, as in the known processes, to pulverise the tobacco starting material into tobacco dust in a dry grinding process.

This time-consuming and costly process is completely eliminated because the tobacco particles can be processed exactly in the form in which they are yielded by the tobacco-processing factories. It is merely necessary to perform a classifying process e.g., with graders or screens, if it is desired to separate a particular tobacco particle fraction for producing a covering or wrapping foil. Veins are merely broken and brought to a particle size of diameter 1 to ID mm. If the natural tobacco debris obtained does not contain adequate quantities of small particles as required to produce wrapping and covering foils the tobacco debris and veins can be pulverised in a grinding process to a particle size of max. 1 mm, but this is much simpler than the grinding process in the known methods.

A further advantage is that the inventive process permits the production of a foil from a granulate whereof the solid content can be increased up to three times, compared with the conventional process. This results in considerable economies on solvents, so that energy is saved when drying the tobacco foil and recovering the solvent. Thus the drying temperature can, in practice, be room temperature and the drying apparatus and suction installation can be much smaller and simplier.

A further important advantage is that the binder content i.e. the cellulose derivative content can be reduced by up to SOpercent leading to a better flavor on smoking of the foil according to the invention, greatly impaired in the known foils by the high cellulose content. By the careful water-free treatment of the tobacco in performing the process of the invention the color and aroma are not lost.

The filler foil produced by the process of the invention has a particularly good bulk and filling capacity.

We claim as our invention:

1. A process for the production of tobacco foils from tobacco, binders and solvents which comprises the steps of:

a. mixing tobacco particles in a size range of 0 to l0 mm with a solvent soluble, finely ground, cellulose derivative, in particle form selected from the group consisting of methyl cellulose, methylpropyl cellulose, acetyl cellulose and ethyl cellulose, and having a particle size of 0 to 0.2 mm to provide tobacco particles having cellulose particles loosely deposited therein but not completely covering the surface of the tobacco particles;

b moistening the so mixed tobacco particles containing said loosely deposited cellulose particles with an organic solvent in an amount to insure superficial swelling of said cellulose and conversion of said cellulose into a jelly-like state to provide a moist, solvent containing brittle tobacco granulate without wetting the tobacco mass and forming a pulp;

c. pressing the brittle solvent containing granulate into a tobacco foil; and

d. removing, by devolatilization, said organic solvent from said foil.

2. A process according to claim 1, characterized in that the tobacco particles are natural debris from tobacco leaf and vein material.

3. A process according to claim 1 characterized in that the organic solvent is selected from the group consisting of readily volatile alcohols, chlorinated hydrocarbons, ketones, ethers, esters and mixtures thereof.

4. A process according to claim 1 wherein said tobacco particles utilized in step (a) is a predetermined size fraction provided by classifying a natural tobacco debris into predetermined fractions, each fraction determinative of the utilization of the tobacco foil provided by step (c).

5. A process according to claim 1 characterized in that a softener is added to the moistening step (b).

6. A process according to claim 5 characterized in that the softener is a glycol.

7. A process according to claim 6 characterized in that the glycol is selected from the group consisting of methylene glycol, diethylene glycol and l,3-butylene glycol. 

1. A PROCESS FOR THE PRODUCTION OF TOBACCO FOILS FROM TOBACCO, BINDERS AND SOLVENTS WHICH COMPRISES THE STEPS OF: A. MIXING TOBACCO PARTICLES IN A SIZE RANGE OF 0 TO 10 MM WITH A SOLVENT SOLUBLE, FINELY GROUND, CELLULOSE DERIVATIVE, IN PARTICLE FROM SILECTED FROM THE GROUP CONSISTING OF METHYL CELLULOSE, METHYLPROPYL CELLULOSE, ACETYL CELLULOSE AND ETHYL CELLULOSE, AND HAVING A PARTICLE SIZE OF 0 TO 0.2 MM TO PROVIDE TOBACCO PARTICLES HAVING CELLULOSE PARTICLES LOOSELY DEPOSITED THEREIN BUT NOT COMPLETELY COVERING THE SURFACE OF THE TABOCCO PARTICLES; B. MOISTENING THE SO MIXED TOBACCO PARTICLES CONTAINING SALD LOOSELY DEPOSITED COLLULOSE PARTICLES WITH AN ORGANIC SOLVENT IN AN AMOUNT TO INSURE SUPERIFICIAL SWELLING OF SAID CELLULOSE AND CONVERSION OF SAID CELLULOSE INTO A JELLY-LIKE
 2. A process according to claim 1, characterized in that the tobacco particles are natural debris from tobacco leaf and vein material.
 3. A process according to claim 1 characterized in that the organic solvent is selected from the group consisting of readily volatile alcohols, chlorinated hydrocarbons, ketones, ethers, esters and mixtures thereof.
 4. A process according to claim 1 wherein said tobacco particles utilized in step (a) is a predetermined size fraction provided by classifying a natural tobacco debris into predetermined fractions, each fraction determinative of the utilization of the tobacco foil provided by step (c).
 5. A process according to claim 1 characterized in that a softener is added to the moistening step (b).
 6. A process according to claim 5 characterized in that the softener is a glycol.
 7. A process according to claim 6 characterized in that the glycol is selected from the group consisting of methylene glycol, diethylene glycol and 1,3-butylene glycol. 